Uppermost crustal structure regulates the flow of the Greenland Ice Sheet

• Published in: Nature Communications
• Main Authors: Jones, G. A., Ferreira, A. M. G., Kulessa, B., Schimmel, M., Berbellini, A., Morelli, A.
• Other Authors: Ser Cymru II Program in Low Carbon Energy and the Environment, RCUK | Natural Environment Research Council
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2021
• Subjects: General Physics and Astronomy; General Biochemistry, Genetics and Molecular Biology; General Chemistry; Greenland; glacier; greenlandic; Ice Sheet; Iceland; Jakobshavn; Petermann glacier
• Online Access: http://dx.doi.org/10.1038/s41467-021-27537-5; https://www.nature.com/articles/s41467-021-27537-5.pdf; https://www.nature.com/articles/s41467-021-27537-5

Abstract The flow of the Greenland Ice Sheet is controlled by subglacial processes and conditions that depend on the geological provenance and temperature of the crust beneath it, neither of which are adequately known. Here we present a seismic velocity model of the uppermost 5 km of the Greenlandic crust. We show that slow velocities in the upper crust tend to be associated with major outlet glaciers along the ice-sheet margin, and elevated geothermal heat flux along the Iceland hotspot track inland. Outlet glaciers particularly susceptible to basal slip over deformable subglacial sediments include Jakobshavn, Helheim and Kangerdlussuaq, while geothermal warming and softening of basal ice may affect the onset of faster ice flow at Petermann Glacier and the Northeast Greenland Ice Stream. Interactions with the solid earth therefore control the past, present and future dynamics of the Greenland Ice Sheet and must be adequately explored and implemented in ice sheet models.